Funded by an ERC Advanced Grant and led by Gaëtan Kerschen, an aeronautical engineer at the University of Liège, the ENTIRE project aims to develop a new generation of vibration tests for aeronautical and space structures, such as aircraft, launchers and satellites. The project aims to bridge the major gap that remains between scientific theory and industrial practice. Research will also find applications in the field of neuroscience, to better characterise the seizures of patients suffering from epilepsy.
N
onlinear vibration theory is a branch of mechanics and applied physics that studies vibratory systems in which the relationships between the applied forces and the system responses are not proportional (unlike linear systems). Since the seminal work of Henri Poincaré at the end of the 19th century, this theory has made considerable progress, particularly with the development of numerical methods in the 1970s.
These advances have enabled us to gain an in-depth understanding of complex dynamic phenomena and to predict them using sophisticated numerical models. However, these scientific advances have had so far little impact on current industrial practices, which are still largely based on the simplifying assumption of linearity. This traditional approach is now proving inadequate considering the growing environmental requirements imposed by the aerospace industry," explains Gaëtan Kerschen, an engineer in the A&M research unit at ULiège. Indeed, modern structures, which are lighter and more flexible thanks in particular to the use of advanced materials, inevitably run the risk of exhibiting nonlinear behaviour that can be dangerous, but potentially beneficial if properly managed."
In this context, the ENTIRE (Experimental Continuation in Nonlinear Dynamics: Aerospace Engineering and Beyond) project proposes a radically new strategy: to develop an innovative experimental methodology capable of identifying, in real time and without the need for a prior model, the entire bifurcation diagram of a nonlinear system. "This approach is based in particular on feedback control techniques, which guarantee the stability of the measured responses. To complement this control-based approach, a complementary strategy based on artificial intelligence and machine learning will be implemented." These advanced tools will enable rapid and accurate analysis of the complex dynamic behaviours observed during testing.
The potential of the methodology will be validated in real-life industrial applications, such as jet engine components and even an entire aircraft. These practical applications will reinforce the industrial relevance and interdisciplinary scope of the proposed methodology. "The test campaigns will be based on collaboration with the company V2i, located in the Liège Science Park, which specialises in vibration testing". The team will also be able to carry out wind tunnel tests at ULiège's School of Engineering, which has a multi-disciplinary subsonic wind tunnel that is ideal for aerodynamic analysis.
The generic nature of the approach proposed by the ENTIRE project also opens up prospects well beyond the aerospace sector. For example, collaborations have already been initiated in the medical field with the NeuroMarseille Institute : "We are going to work with Dr Jirsa to develop protocols for measuring epileptic episodes in order to gain a better understanding of the phenomenon and its onset.
The ENTIRE project marks a significant step forward by bringing together for the first time the three essential components of nonlinear vibration analysis: fundamental theory, advanced numerical simulation and an innovative experimental approach. Ultimately, this convergence promises to provide total control of nonlinear vibration phenomena, guaranteeing safer, more efficient and durable structures for tomorrow's industry. The methodology proposed as part of the ENTIRE project could also benefit other applications such as micro-resonators (MEMS) or lasers in physics.
The ENTIRE project follows a remarkable career. It is the third such grant that Gaëtan Kerschen has received from the European Research Council, following an ERC Starting Grant (2012-2017) for his NOVIB (The Nonlinear Tuned Vibration Absorber) project on the design and testing of a prototype aircraft wing vibration damper, and its implementation with an ERC Proof of Concept Grant NI2D (2017-2019) to market his nonlinear vibration analysis software to companies active in the space, automotive and mechanical engineering sectors.
nGHOST2Market to track stray light from space telescopes and GrAVITe, an optical gyroscope to stabilise high-precision instruments.
The NBS4U project, coordinated by Jacques Teller, has just secured funding to develop, test, and implement nature-based solutions to enhance the climate resilience of peri-urban areas in the Meuse-Rhine region.
Under the 5th Interreg VI Meuse-Rhine call, 3 research projects have been accepted at ULiège. These include the IMPRESS project, coordinated at ULiège by Méryl PAQUAY (Faculty of Medicine, Department of Public Health Sciences).
